Apex seal assembly for rotary mechanisms

ABSTRACT

An apex seal assembly for each apex portion of a rotary mechanism which is disposed in an apex groove radially extending in the apex portion of the rotor. The apex groove is constructed and arranged to communicate with circular grooves for gas sealing rings formed in each end face of the rotor. The apex seal assembly comprises a plurality of blade members disposed in the apex groove. One blade is radially slidable in the apex groove and engages the peripheral wall of the housing of the rotary mechanism and the other blades are axially slidable to abut the end walls of the housing of the rotary mechanism. At least two of said other blade members are positioned to engage the gas sealing rings to provide a fluid seal. A biasing means is disposed in the apex groove to urge the other blade members axially outwardly of the apex groove. The plurality of blade members having abutting inclined surfaces which coact to divide the biasing force into axially and radially directed reaction force components which resiliently urge the one blade member into constant engagement with the peripheral wall of the housing and the other blades into continuous engagement with the housing end walls and maintain said two other blade members in contact with the gas seal rings.

nite States Patent [191 Jones [4 1 Dec. 10, 1974 APEX SEAL ASSEMBLY FOR ROTARY MECHANISMS Related US. Application Data [63] Continuation-impart of-Ser. No. 181,084, Sept. 16,

1971, abandoned.

[52] US. Cl 418/121, 418/61 A, 418/143 [51] Int. Cl. F016 19/02 [58] Field of Search ..418/1l3, 120,121,117,

[56] References Cited UNITED STATES PATENTS 3,251,541 5/1966 Paschke 418/61 A Primary ExaminerC. J. Husar Attorney, Agent, or F inn-Arthur Frederick [57] ABSTRACT An apex seal assembly for each apex portion of a rotary mechanism which is disposed in an apex groove radially extending in the apex portion of the rotor. The apex groove is constructed and arranged to communicate with circular grooves for gas sealing rings formed in each end face of the rotor. The apex seal assembly comprises a plurality of blade members disposed in the apex groove. One blade is radially slidable in the apex groove and engages the peripheral wall of the housing of the rotary mechanism and the other blades are axially slidable to abut the end walls of the housing of the rotary mechanism. At least two of said other blade members are positioned to engage the gas sealing rings to provide a' fluid seal. A biasing means is disposed in the apex groove to urge the other blade members axially outwardly of the apex groove. The plurality of blade members having abutting inclined surfaces which coact to divide the biasing force into axially and radially directed reaction force components which resiliently urge the one blade member into constant engagement with the peripheral wall of the housing and the other blades intocontinuous engagement with the housing end walls andmaintain said two other blade-members in contact with the gas seal rings.

7 Claims, 9 Drawing Figures PATENFEDHEEWW 3.853.439

sum 2 0F 5 INVEN TOR.

(WA/P165 Jan/5 APEX SEAL ASSEMBLY FOR ROTARY MECHANISMS This patent application is a continuation-in-part of pending U.S. Pat. Application Ser. No. 181,084, filed Sept. 16, 1971, now abandoned.

The invention relates to fluid seals and, more particularly, to an apex seal structure for rotary mechanisms of the type disclosed in the U.S. Pat. to Felix Wankel, No. 2,988,065. In the following description the invention will be described as applicable to an internal combustion engine of the Wankel type, but it is to be recognized that the invention is also suitable for other forms of rotary mechanisms, such as fluid pumps, fluid compressors and fluid motors.

BACKGROUND OF THE INVENTION A rotary mechanism, similar to that disclosed in the aforementioned United States patent, comprises an outer body or housing and an inner body or rotor eccentrically mounted on a crankshaft for rotation in the housing. The outer peripheral surface of the rotor and the adjacent housing walls define a plurality of working chambers which, during relative rotation of the rotor, vary in volume. 1n order to promote efficient operation of the mechanism, particularly when functioning as an internal combustion engine, the chambers are preferably sealed from one another by seal means disposed between the rotor and housing. The seal means include, as exemplified in the U.S. Pats. to Froede, No. 3,142,439, Schagg, No. 3,142,440 and Bentele, No. 3,180,562, apex seal structures which include apex seal assemblies carried by the rotor at the apex portions of the rotor. Each of these apex seal assemblies usually comprise a spring biased blade member carried in a slot in the apex portion of the rotor to project from the latter to engage the end and peripheral wall portions of the housing. The seal means also includes arcuate segmental side seal strips disposed in grooves in the rotor end faces to engage the housing end walls. An additional element usually povided in the conventional seal means, is an intermediate seal member, commonly referred to as an apex seal pin, which functions to seal the interstices between the blade member and seal strips. Various designs of seal means above'described are disclosed in the following U.S. Patents:

In each of the aforesaid seal means, the apex seal pin is costly to manufacture because it either has to be machined to very close tolerances or machined specifically to match or mate with the side seal strips and apex seal members. Accordingly, attempts have been made to provide a seal means in which the necessity for an apex seal pin is eliminated. One such attempt is disclosed in the U.S. Pat. to Bentele, No. 3,193,188, but the shortcoming of this construction is that it too is costly to fabricate because the notches in the side seal rings must properly mate with the grooves in the apex portions so that the side seal blade members sealingly abut the side walls of the notches in the side seal rings.

Another such effort is disclosed in the U.S. Pat. to Paschke, No. 3,251,541, which employs gas from the working chambers as 'a biasing force acting on seal blade elements. The problem with this construction is that the biasing gas pressure varies widely during one complete cycle of operation and for different modes of engine operation. For this reason and the fact that the seal blades are subjected to reversed acceleration forces, the integrity of a seal between the blades and the side gas seals cannot be maintained.

Accordingly, it is an object of the present invention to provide for a rotaty mechanism an effective apex seal assembly which is relatively simple and inexpen' sive to fabricate.

It is another object of this invention to provide fora rotary mechanism an apex seal assembly which engages and maintains a sealing relationship with side gas sealing rings without the need for an apex seal pin.

It is a further object of 'the present invention to provide an apex seal assembly which effectively seals the interstices between the rotor periphery and the housing peripheral wall and between the rotor end faces and the adjacent housing end walls.

A still further object is to provide an apex seal assembly which coacts with a side gas sealing ring to provide a fluid seal, the integrity of which is maintained notwithstanding wear of the apex seal assemblies and the gas sealing ring.

SUMMARY OF THE INVENTION Therefore, the invention contemplates an improved apex seal assembly for a rotary mechanism having a housing with axially spaced end walls and a peripheral wall interconnecting the end walls to form a cavity therebetween and a rotor mounted within the cavity for rotation on an axis eccentric to the housing axis. The rotor has axially spaced end faces and a peripheral surface so shapedas to provide the rotor with a plurality of circumferentially spaced apex portions, the rotor peripheral surface defining with the housing walls a plurality of working chambers which vary in volumetric size as the rotor rotates within the housing.

The improved apex seal assembly for each apex portion of the rotor comprises, in combination with side gas sealing rings carried in a circular groove in each end face of the rotor, an apex groove at each apex portion of the rotor ex'tendingaxially from one side face of the rotor to the other and radially inwardly to a point in communication with the circular grooves for the side gas sealing rings. In addition, the assembly includes a first blade means disposed in the apex groove for slidable movement radially relative to the rotor, a second blade means disposed for slidable movement in the apex groove in an axial direction and arranged to abut said first blade means and the end walls of the housing,

, and a third blade means disposed in the apex groove for axial slidable movement and abutment against said second blade means and the side gas sealing rings. A resilient biasing means is positioned in the apex groove to urge the third blade means in a direction out of the apex groove toward the end faces of the rotor. The first, second and third blade means are provided with abutting surface portions coacting so that the oppositely directed axial forces exerted by the resilient biasing means is divided into plural sets of axially and radially directed force components to simultaneously urge the second blade means into contact against the end wall surfaces of the housing and the first blade means into impingement against the surface of the peripheral wall of the housing. Also, the third blade means is biased into contact with the gas sealing ring. Thus, the improved apex seal assembly provides a substantially fluid tight seal at the peripheral and end walls of the housing and at the gas sealing ring so that each working chamber is substantially isolated from the other working chambers.

In one embodiment of the invention the second blade means consists of two blades, one blade being disposed adjacent to and in abutment against each of the opposite end portions of the first blade means. The biasing means is positioned to engage and urge each of the two blades axially and radially against the first blade memher.

In another embodiment of the invention the first means is a blade member which is somewhat L-shaped and disposed in the apex groove with one leg extending radially adjacent and in contact with the surface of one of the housing end walls and the other leg extending axially and abutting the peripheral housing wall. The

rbutting inclined surfaces of the first blade and the second blade means are so inclined that the axially and radially force components urge the first blade in abutment against the peripheral housing wall and the one leg of the first blade in abutment against the adjacent housing end wall.

BRIEF DESCRIPTION OF THE DRAWING The invention will be more fully understood from the following detailed description thereof when considered in connection with the accompanying drawing wherein several embodiments of the invention are illustrated by way of example and, in which:

FIG. 1 is a longitudinal cross-sectional view through a rotary mechanism of the internal combustion type having an apex seal assembly according to the present invention;

FIG. 2 is a cross-sectional view taken substantially along line 2-2 of FIG. 1;

FIG. 3 is an enlarged fragmentary view in crosssection showing on an enlarged scale the apex seal assembly illustrated in FIGS. 1 and 2;

FIG. 4 is an end elevational view of the apex seal assembly shown in FIG. 3 taken along line 4-4 of FIG. 3;

FIG. 5 is a further enlarged fragmentary view of the apex seal assembly prior to wear of the assembly components;

FIG. 6 is a view similar to FIG. 5 showing the apex seal assembly components after wear;

FIG. 7 is a view similar to FIG. 3 showing a second embodiment of the apex seal assembly of this invention;

FIG. 8 is a view similar to FIGS. 3 and 7 of an apex seal assembly according to a third embodiment of this invention; and

FIG. 9 is a fragmentary view, in elevation, showing one form of gas seal ring which coacts with the apex seal assembly of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS type which has an apex seal assembly 12 according to one embodiment of this invention for each apex portion of the rotor 16 of the mechanism. It is to be understood that while the apex seal assemblies 12 are shown in FIGS. 1 and 2 as incorporated in a rotary internal combustion engine of the Wankel type disclosed in US. Pat. No. 2,988,065, the invention is not limited to such application but may be employed in fluid motors and other rotary mechanisms constructed and arranged for the pumping or compression of fluid without departing from the scope and spirit of this invention. Also, and again for convenience, although in rotary mechanisms of the Wankel type either the inner body or the outer body or both, may be rotatable, the following description will be in terms of a mechanism in which the outer body or housing is fixed and inner body or rotor is rotated.

The rotaty mechanism 10 comprises a casing or housing 14 and an inner body or rotor 16 eccentrically mounted on a crankshaft 18 for-rotation within the housing. The housing 14 consists of a central body portion 20 and opposite end walls 22 and 24'suitably secured together by tie bolts (not shown) or other connecting means known to those skilled in the art. The central body portion 20 has an internal peripheral wall surface 26 having a substantially epitrochoidal shape which defines with the end wall surfaces 28 and 30 of end walls 22 and 24, respectively, a cavity in which rotor 16 is disposed for rotation.

The rotor 16 has a body portion having opposite end faces 32 and 34 (see FIG. 1) which are shaped to have three spaced apex portions 36 interconnected by arcuate peripheral surfaces 38. The rotor defines with the peripheral wall surface 26 and end wall surfaces 28 and 30 of housing 14, three working or combustion chambers A, B and C each of which progressively vary in volumetric size as the rotor rotates within the housing cavity.

To provide for combustion of fuel within the working chambers, an intake port 42 (see FIG. 2) is provided in housing 14 and communication with a fuel supply source (not shown) to introduce fuel and air into working chamber A. The fuel and air mixture following compression is ignited by an ignition means, such as spark plug 44, mounted on housing 14 andin communication with the working chamber C. The exhaust gases are discharged from the working chambers via an exhaust port 46 located to communicate with chamber B.

The maximum operating efficiency of rotary mechanism 10 is, in part, dependent upon maintaining each of the working chambers A, B and C in as fluid tight an isolation as possible. To substantially seal each of the working chambers from each other, the rotary mechanism is provided with apex seal assemblies 12 and gas seal rings 48 and 50 as best shown in FIGS. 3 and 4, each gas seal ring 48 and 50 is mounted for axially slidable movement in an annular groove 52 formed in each rotor end face 32 and 34. Each of the gas seal rings 48 and 50 is biased in a direction out of its associated groove 52 and into abutment with the adjacent housing end wall surface 32 or 34, by a wavy spring washer 54. The gas seal rings 48 and 50 may be of one piece solid construction or be of split construction such as illustrated in FIG. 9. As best shown in FIGS. 3, 4, 5 and 6 each apex seal assembly 12 coacts with seal rings 48 and 50 so as to substantially maintain the working chambers out of communication with each other.

Each apex seal assembly 12 comprises, a plurality of abutting seal blade members 56, 58, 60, 62 and 64 and a biasing means, such as a spring 66, disposed within a groove 68 formed in each apex portion 36 of rotor 12. The groove 68 extends axially from the opposite sides 32 and 34 of rotor 16 and from peripheral surfaces 38 of the rotor radially inwardly to a point in communication with gas seal ring grooves 52.

The seal blade member 56 is substantially trapezoidal in shape and rectangular in cross section. The long base or sealing edge 70 is dimensioned to extend substantially the width of the internal surface 26 of housing portion 20 while its thickness is slightly less than the width of groove 68 as is shown in FIG. 4. The inclined I opposite end edges 72 and 74, which are contiguous with sealing edge 70 and the short base edge 76, abut complementarily inclined edge surfaces 78 and 80 of side seal blade members 58 and 60, rspectively. The seal blade member 56 is free to move radially relative to groove 68 and is resiliently biased in a direction outwardly of the groove by means hereinafter fully explained so that sealing edge 70 abuts surface 26 of housing 14 to separate adjacent working chambers from each other such as working chambers A and B as viewed in FIGS. 2 and 4. Fluid leakage between chambers A and B which attempts to bypass seal blade 56 is prevented by sea] blade 56 abutting one or the other of the side walls of groove 68, such as is shown in FIG. 4, which sealing contact occurs by reason of the fluid pressure differential across seal blade 56.

Fluid leakage between chambers A and B, through the space between juxtaposed surfaces 28 32 and 34, is prevented by the sealing contact of blade members 58 and 60 against housing end wall surfaces 28 and 30. The blade members 58 and 60 are each trapezoidal in configuration and are disposed with their respective sealing edge portions 82 and 84 (longer base portions) in abutment against the adjacent end wall surfaces 28 and 30. The blade members 58 and 60 are each dimensioned so that, when inclined side edge surface 78 is in abutment against the inclined end edge surface 72 of blade member 56, the ends of each of the sealing edge surfaces 82 and 84 are in close spaced relation to the outer peripheral surface 86 of side gas seal rings 48 and 50.

To seal the leakage flow path in the space between the ends of blade members 58 and 60 and the adjacent side gas seal rings 48 and 50, a third seal means in the form of blade members 62 and 64 is provided in apex seal assembly 12. Each blade member 62 and 64 is substantially in the shape of a right triangle and is disposed adjacent to one of the blade members 58 and 60. Each blade member is dimensioned and constructed so that its hypotenuse edge portion 90 is complementary to and abuts an inclined side edge portion 92 of the associated blade member 62 or 64 and its base leg portion 94 abuts in sealing contact'the outer peripheral surface 86 of the adjacent side gas seal ring 48 or 50. v

The blade members 58, 60, and 64 are slightly narrower in thickness than the width of groove 68 and are preferably substantially the same thickness as blade member 56 so that the blade members'are free to slidably move axially within groove 68 while blade member 56 is free to move radially relative to groove 68 under the force exerted by spring 66. Since it is impractical for manufacturing reasons to make internal surface 26 a true epitrochoid wherein the sealing edge of blades 56 can ride exactly in contact withinternal surface 26, blades 56 must be resiliently biased so that the blades 56 may move slightly inwardly of their respective grooves 68. Obviously, any slight inward movement of blades 56 will be transmitted through their associated blades 58 and 60 to blades 62 and 64 which are thereby cammed inwardly against the force of the associated springs 66.

The spring 66, forming part of each apex seal assembly 12, is positioned within groove 68 and between seal blade members 56, 58, 60, 62 and 64 and constructed and arranged to abut seal blade members 62 and 64. The spring 66 is assemblied so that it is under compression and exerts forces on blade members 62 and 64 in a direction axially and outwardly of groove 68. These oppositely directed axial forces produce composite reaction forces which are divided into axially and radially directed force components by the coaction of abutting inclined surfaces and 92 of blade members 62, 64, 58 and 60. As viewed in FIG. 3, the radial reaction force components are directed upwardly and toward internal surface 26 of the housing and are transmitted, through side blade members 58 and 60, to opposite end portions of seal blade member 56. Since the portion of apex seal assembly-l2 adjacent .oneend face of rotor v16 is a mirror image of the portion adjacent the opposite rotor end face, the radially directed reaction force components are substantially equal so that seal blade member 56 is maintained in sealing contact with internal surface 26 by a substantially uniformly distributed radial force. Also, the axially directed reaction force components exerted upon side blade members 58 and 60 are substantially equal and directed toward the end wall surfaces 28 and 30 of end walls 22 and 24, respectively, tothereby resiliently urge and maintain side blade members 58 and 60 in sealing, slidable engagement with end wall surfaces 22 and 24. The reactive radially directed force components produced by the 00- action of the abutting surfaces 90 and 92 of blade members 58, 6.0, 62 and 64, functions to maintain the respective sealing surfaces 94 of blade members 62 and 64 in sealing contact with the outer peripheral surfaces 94 of side 'gas seal rings 48 and 50.

Obviously, in the fabrication of apex seal assemblies 12 no extremely accurate or difficult machining or assembly steps of the blade'members 62 and 64 or side seal rings 48 and 50 is required to bring sealing surface 94 of blade members 62 and 64 into contact with side seal rings 48 and 50.

As best illustrated in FIGS. 5 and 6, the sealing contact of the respective sealing surfaces of blade members 56, 58, 60,62 and 64 against surfaces 26, 30,

32 and 94 is maintained as the sealing surfaces of the blade members wear. The wear which may occur in the abutting surfaces 94 and 86'is negligible since there is relatively little relative movement between blade members 62 and 64 and side seal rings 48'and 50. Thus, apex seal assembly 12, maintains an effective seal between adjacent working chambers A, B and C for a relatively long operative life of the rotary mechanism.

In FIG. 7 is shown an apex assembly according to a second embodiment of this invention which differs from apex seal assembly 12 in that one of the side seal blade members'is omitted and the blade member is L- shaped and is biased to sealingly engageboth the inter- I nal peripheral wall surface and one of the side wall surfaces. The parts of apex seal assembly 100 corresponding to a like part of apex seal assembly 12 will be designated by the same reference number but with a suffix A added thereto.

Apex seal assembly 100 comprises a seal blade member 56A which is L-shaped and dimensioned so that a leg 102 extends in abutment along its sealing surface 70A across almost the entire width of internal wall surface 26A and the other leg 104 extends in abutment along its sealing surface 106 against end wall surface 28A of the housing. The leg 104 of blade member 56A is of such length that sealing surface 106 extendsalong wall surface 28A substantially the entire distance be tween surface 26A and the outer surface of side gas seal ring 48A. Since the axially directed reaction force components of the forces produced by spring 66A and which act on blade member 56A are not balanced as in the apex assembly 12, the net effective axially directed force on blade member 56A is toward wall surface 28A to thereby maintain sealing surface 106 in engagement with end wall surface 28A. Mainifestly, the axial force components produced by the abutment of surfaces 90A and 92A of blade member 60A and leg 104 and blade members 62A and 64A, are substantially equal and opposite. However, the abutting inclined surfaces 80A and 74A of blade members 60A and 56A, respectively, produces a net axial reaction force component on blade member 56A which is directed toward housing end wall surface 28A and is unopposed. Thus, blade member 56A, along sealing surface 106, is constantly biased in contact with end wall surface 28A.

In FIG. 8 is shown an apex seal assembly 110 accordingto a third embodiment of this invention. The parts of apex seal assembly 110 corresponding to like parts of apex seal assembly 100 shall be hereinafter designated by the same number but with the suffix B added thereto.

The apex seal assembly 110 is similar to apex seal assembly 100 shown in FIG. 7 and only differs in that leg 1048 of blade member 56B is shorter in length than leg 104 of blade member 56A and abutting blade member 64B is larger in size than blade member 64A. The blade members 56B, 60B, 62B and 64B cooperate to achieve substantially the same results as those achieved for by apex seal assembly 100, except that sealing contact along housing end wall surface 288 is achieved by a sealing surface 1068 and a sealing surface 112 on sealing blade 6413.

It is believed now readily apparent that the present invention provides an apex seal assembly in combination with side gas seal rings which is relatively inexpensive to manufacture and assemble by reason of its simplicity of construction. It is an apex seal assembly which effectively isolates the working chambers from each other without the need for the conventional seal pins. It is an apex seal assembly wherein the sealing elements maintain sealing engagement as wear occurs so that the assembly has a relatively long operative life.

Although several embodiments of the invention have i been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes can be made in the arrangement of parts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

What is claimed is:

1. An apex seal assembly for a rotary mechanism having a housing with axially spaced end walls and a peripheral wall interconnecting the end walls to form a multi-lobed cavity therebetween and a rotor mounted within said cavity for rotation on an axis eccentric to the housing, the rotor having axially spaced side faces and a peripheral surface consisting of a plurality of circumferential spaced apex portions for forming with the housing walls a plurality of working chambers which vary in volumetric size as the rotor rotates within the housing cavity, the apex seal assembly for each apex portion of the rotor comprises in combination with a side seal ring carried in a circular groove in each end face of the rotor:

a. an apex groove at the apex portion of the rotor extending axially from one side face of the rotor to the other and radially inward to communicate with the circular groove for the side seal ring;

b. a first blade means disposed to extend axially within the apex groove and projecting radially therefrom adjacent said peripheral wall;

c. a second blade means disposed to extend radially within the apex groove and project axially therefrom beyond one of the side faces of the rotor;

d. a third blade means disposed in' the apex groove radially inward of said second blade means, and in abutment against the side seal ring in said one of the side faces of the rotor;

e. said second blade means having radially spaced opposite end edge portions which extend axially in ward of said one of the side faces of the rotor in a converging direction; I

f. the first and third blade means each having an in-, clined edge portion which is complementary to and in abutment against the converging end edge portions of said second blade means; and

g. a spring for exerting an axially directed force on the third blade means so that the reaction forces between the first, second and third blade means at their abutting edge portions simultaneously urge the third blade means in a radial direction into sealing contact with the side seal ring, the second blade means in axial and radial directions into sealing engagement with the adjacent housing side wall and against the first blade means, and said. first blade means in radial and axial directions into sealing contact with the peripheral wall and away from said adjacent housing side wall.

2. The apparatus of claim 1 wherein said second blade means is trapezoidal in shape with the longer side being disposed outwardly of the adjacent side face of the rotor;

3. The apparatus of claim 1 wherein said first blade means is L-shaped with one leg portion thereof extending adjacent to the other of the side faces of the rotor and a fourth blade means disposed within the apex groove in abutment against said one leg portion and projecting beyond the other of the side faces of the rotor.

4. The apparatus of claim 1 wherein said first, second and third blade means are each a single element.

5. The apparatus of claim 1 wherein said first blade means is a single L-shaped first blade member and said second blade means includes one second blade member abutting one end portion of the first blade member and wherein said third seal means includes two blade members, one of which is disposed in abutment against means includes two unitary third blade members located adjacent each end of the apex groove to abut the adjacent gas sealing ring and the adjacent second blade member. 7

7. The apparatus of claim 1 wherein said first and second blade means are dimensioned such that an imaginary projection of the abutting end edge portions intersects the adjacent end wall of. the housing.

UNITED STATES PATENT OFFICE flERTIFICATE OF CORRECTIGN PATENT NO. I 3, 853,439

DATED December 10, 1974 INVENTOR(S) Charles Jones It is certified that error appears'in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

IN THE SPECIFICATION:

Column 3, line 23, first Word appearing rbutting" should be "abutting- Column 5, line 20, the Word "rspectively" should read respectivelyline 6 1,,after the number "60" the numher --62-- I should appear 7 Column 6, line 15, the word "ass-emblied" should read --assembled--. I line 63, after the word "apex" the word --seal-- should be inserted.

Signed and sealed this 20th day of May 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 

1. An apex seal assembly for a rotary mechanism having a housing with axially spaced end walls and a peripheral wall interconnecting the end walls to form a multi-lobed cavity therebetween and a rotor mounted within said cavity for rotation on an axis eccentric to the housing, the rotor having axially spaced side faces and a peripheral surface consisting of a plurality of circumferential spaced apex portions for forming with the housing walls a plurality of working chambers which vary in volumetric size as the rotor rotates within the housing cavity, the apex seal assembly for each apex portion of the rotor comprises in combination with a side seal ring carried in a circular groove in each end face of the rotor: a. an apex groove at the apex portion of the rotor extending axially from one side face of the rotor to the other and radially inward to communicate with the circular groove for the side seal ring; b. a first blade means disposed to extend axially within the apex groove and projecting radially therefrom adjacent said peripheral wall; c. a second blade means disposed to extend radially within the apex groove and project axially therefrom beyond one of the side faces of the rotor; d. a third blade means disposed in the apex groove radially inward of said second blade means, and in abutment against the side seal ring in said one of the side faces of the rotor; e. said second blade means having radially spaced opposite end edge portions which extend axially inward of said one of the side faces of the rotor in a converging direction; f. the first and third blade means each having an inclined edge portion which is complementary to and in abutment against the converging end edge portions of said second blade means; and g. a spring for exerting an axially directed force on the third blade means so that the reaction forces between the first, second and third blade means at their abutting edge portions simultaneously urge the third blade means in a radial direction into sealing contact with the side seal ring, the second blade means in axial and radial directions into sealing engagement with the adjacent housing side wall and against the first blade means, and said first blade means in radial and axial directions into sealing contact with the peripheral wall and away from said adjacent housing side wall.
 2. The apparatus of claim 1 wherein said second blade means is trapezoidal in shape with the longer side being disposed outwardly of the adjacent side face of the rotor.
 3. The apparatus of claim 1 wherein said first blade means is L-shaped with one leg portion thereof extending adjacent to the other of the side faces of the rotor and a fourth blade means disposed within the apex groove in abutment agAinst said one leg portion and projecting beyond the other of the side faces of the rotor.
 4. The apparatus of claim 1 wherein said first, second and third blade means are each a single element.
 5. The apparatus of claim 1 wherein said first blade means is a single L-shaped first blade member and said second blade means includes one second blade member abutting one end portion of the first blade member and wherein said third seal means includes two blade members, one of which is disposed in abutment against said second blade member and the gas sealing ring while the other third blade member is disposed in abutment against said other end portion of the first blade member and the said gas sealing ring.
 6. The apparatus of claim 1 wherein said first blade means is a unitary first blade member, said second blade means includes two unitary second blade members positioned in abutment against opposite end portions of first blade member and wherein said third seal means includes two unitary third blade members located adjacent each end of the apex groove to abut the adjacent gas sealing ring and the adjacent second blade member.
 7. The apparatus of claim 1 wherein said first and second blade means are dimensioned such that an imaginary projection of the abutting end edge portions intersects the adjacent end wall of the housing. 